How can I improve my Grade? From a B to an A

I am a Northern Irish student doing A-Level Biology with CCEA. I was happy with my recent AS results; especially when I thought I would fail Biology as my teachers marked harshly the entire year.

From what I could see, I was half way between an A Grade and a B grade in Biology in AS. This in turn has driven me to ask myself the question I never thought I would ask myself: Could I get an A?

I enjoy Biology but always seem to never reach my full potential in the subject. It seems that I can never reach that goal of an A. Thus, I have driven myself to post here. I am looking for first hand experience from people who have been in my position also. I really wish to make my final year one to remember and I feel I can do it.

For reference, I usually start proper revision about March/April time doing Past Papers which always helped me achieve my grades. I never found notes to be useful as I found they get tacky and childish.

What can I do to change my revision techniques to improve my grade? I really wish to get an A in Biology as A2 is 60% of the A-Level and thus I have the opportunity to achieve it.

Thank you in advanced.